Study On The Properties Of Waste Incineration Slag Composite Materials

Waste incineration slag is the main by-product in the process of waste incineration power generation.It has the advantages of high mechanical strength,abundant pore structure and multiple active sites.In dry state,the slag of waste incineration furnace is usually powdery,which is difficult to recycle,easy to drain and easy to block.In this paper,waste incineration slag particles（WIS）were prepared by kneading calcination,and MOF solution impregnation,Fe₂O₃ doping and iron slag doping were adopted.MOF loaded waste incineration furnace slag（MX-WIS）,Fe₂O₃ doped waste incineration furnace slag（Fex-WIS）and iron slag doped waste incineration furnace slag（Xx-WIS）were prepared and used as the substrate for phosphorus removal in constructed wetland to realize the resource utilization of waste incineration furnace slag.（1）The optimal pretreatment method of waste incineration slag is ultrasonic cleaning for 0.5 h.The pre-treated waste incineration slag particles are used to prepare WIS.Under the conditions of dosage of 1.5 g/L,initial phosphorus concentration of 30 mg/L and p H value of solution of 7,the equilibrium adsorption capacity is 1.675 mg/g.（2）The characterization results of Mx-WIS series materials showed that the granulation process enriched the pore structure of WIS materials,and the introduction of ZIF-8 grains also increased the number of surface active sites.The response surface model was used to optimize the impregnation solution concentration and reaction conditions.The optimal loading solution concentration was 4.99 g/L,p H value was 8.16,initial phosphorus concentration was 37.67 mg/L,and the equilibrium adsorption capacity could reach 2.406 mg/g under the optimal conditions.The adsorption process of Mx-WIS conforms to the quasi-second-order kinetic model.（3）The characterization results of Fex-WIS series materials showed that Fe₂O₃particles were uniformly deposited on the surface and in the pores of the materials,and the content of Fe element increased.Compared with WIS,the parameters of specific surface area and pore volume had no obvious change.The response surface model was used to optimize the doping amount of Fe₂O₃ and the reaction conditions.The optimal Fe₂O₃ doping amount was 15%,p H value was 8.09,and the initial phosphorus concentration was 45 mg/L.Under the optimal conditions,the equilibrium adsorption capacity could reach 3.183 mg/g.The phosphorus adsorption process of Fex-WIS conforms to the quasi-second order kinetic model.（4）The characterization results of Xx-WIS series materials show that iron slag particles accumulate on the surface of the material and in the pores,the content of Fe element increases,and the specific surface area,pore volume and other parameters have little change compared with WIS.The response surface model was used to optimize the doping amount of iron slag and the reaction conditions.The optimal conditions were obtained:the doping amount of iron slag was 17%,the p H value was 8.97,the initial phosphorus concentration was 45 mg/L,and the equilibrium adsorption capacity could reach 3.176 mg/g under the optimal conditions.The phosphorus adsorption process of Xx-WIS conforms to the quasi-second-order kinetic model.（5）Comparatively,Fex-WIS series materials showed the best phosphorus adsorption performance,and Xx-WIS series materials were close to it.Combined with material cost and accessibility,Xx-WIS series materials were selected to conduct subsequent stability and actual wastewater simulation experiments.The results showed that the equilibrium adsorption capacity of X2-WIS material remained at a good level after 5 times desorption and regeneration,and the adsorption effect on simulated secondary effluent was good.Xx-WIS can be used as a low cost,good phosphorus removal effect,easy separation,renewable constructed wetland matrix.